Hydrangea plant named ‘COUSTAR02’

ABSTRACT

A new  Hydrangea  plant named ‘COUSTAR02’ particularly distinguished by having compact habit; and an inflorescence color changing from white to pink to dark red, is disclosed.

Genus and species: Hydrangea paniculata.

Variety denomination: ‘COUSTAR02’.

BACKGROUND OF THE NEW PLANT

The present invention comprises a new and distinct variety of Hydrangeaplant, botanically known as Hydrangea paniculata, and hereinafterreferred to by the variety name ‘COUSTAR02’. ‘COUSTAR02’ originated froman open pollination in Moyenmoutier, France in March 2011 using anunknown female Hydrangea paniculata parent and an unknown male Hydrangeapaniculata parent. Seeds from the open-pollination were taken from thefemale parent and sown and a single plant was chosen in 2013.

‘COUSTAR02’ was first propagated in June 2015 in France. ‘COUSTAR02’ wasfound to reproduce true to type in successive generations of asexualpropagation via softwood cuttings.

SUMMARY

The following are the most outstanding and distinguishingcharacteristics of this new variety when grown under normalhorticultural practices in Boskoop, The Netherlands.

-   -   1. Compact habit; and    -   2. Inflorescence color changing from white to pink to dark red.

DESCRIPTION OF THE PHOTOGRAPHS

This new Hydrangea plant is illustrated by the accompanying photographswhich shows the plant's overall plant habit including form, and foliage.The photographs are of a two year old plant from cuttings grown in a17-cm container. Photos were taken in August 2021 in Boskoop, TheNetherlands. The colors shown are as true as can be reasonably obtainedby conventional photographic procedures.

FIG. 1 shows the overall plant habit of ‘COUSTAR02’.

FIG. 2 shows a close-up of the flowers.

FIG. 3 shows a close-up of the foliage.

DESCRIPTION OF THE NEW VARIETY

The following detailed descriptions set forth the distinctivecharacteristics of ‘COUSTAR02’. The data which define thesecharacteristics were collected from asexual reproductions carried out inBoskoop, The Netherlands. Data was collected on two-year old plantsgrown outdoors in 17 cm square containers in Boskoop, The Netherlands inAugust 2021. The range of day temperatures was 16° C. to 26° C. and therange of night temperatures was 8° C. to 20° C. Color references are toThe R.H.S. Colour Chart of The Royal Horticultural Society of London(R.H.S.), 6^(th) edition (2015).

-   Classification:    -   -   Family.—Hydrangeaceae.        -   Botanical.—Hydrangea paniculata.        -   Common.—Hydrangea.        -   Designation.—‘COUSTAR02’.-   Plant:    -   -   Propagation type.—Vegetative cuttings.        -   Time to produce a finished plant.—Average is twelve months            from propagation to a small, finished plant.        -   Appropriate for what size of container.—Field grown and in            13 in pots or larger.        -   Plant shape.—Short ovate.        -   Average plant height.—39.5 cm.        -   Average plant diameter.—39.2 cm.        -   Growth habit.—Broad spreading-upright.        -   Growth rate.—Low to moderate.        -   Vigor.—Moderate.        -   Heat tolerance.—At least tolerant to USDA Zone 9.        -   Cold tolerance.—Tolerant to USDA Zone 5.        -   Tolerance to wind.—Moderate.        -   Tolerance to rain.—Moderate to high.-   Branches:    -   -   Habit.—Freely branching.        -   Basal branching.—Present.        -   Pinching.—Not required but will improve branching.        -   Lateral branches.—Number of lateral branches per plant:            Average of 10. Length: Average is 17.6 cm, excluding            inflorescence. Diameter: Average is 0.5 cm. Internode            length: Average is 4.5 cm. Appearance and shape: Rounded.            Aspect/angle: Upright; average angle of 60 degrees to main            branch. Strength: Strong. Color, immature: RHS 146D            (Yellow-green). Color, mature: RHS 199A (Grey-brown) and RHS            199B (Grey-brown); Older bark and RHS 197B to RHS 197D            (Greyed-green) and RHS 199A, RHS N199A and RHS N199B            (Grey-brown). Pubescence: Young stems sparsely to moderately            covered with short adpressed hairs, average length: 0.5 mm,            colored green-white; too small and too sparsely present to            be measured with RHS-CC. Lenticels: Stems sparsely to            moderately covered with lenticels, average length 1.5 mm,            average width 0.75 mm, colored RHS 164B (Greyed-orange);            lenticels not visible on mature stems.-   Foliage:    -   -   Arrangement.—Opposite or in whorls of three.        -   Shape.—Ovate.        -   Apex.—Apiculate to acute.        -   Base.—Acute to short attenuate.        -   Margin.—Serrate.        -   Length.—Average is 6.9 cm.        -   Width.—Average is 3.7 cm.        -   Texture.—Upper and lower surfaces: Smooth, moderately            pubescent.        -   Pubescence.—Both sides moderately pubescent with very short            strigose hairs, adpressed on underside of lamina, on upper            side average length: 0.3 mm, colored greyed-white; too small            and too sparsely present to be measured with RHS-CC, on            under side average length: 0.4 mm, colored green-white; too            small and too sparsely present to be measured with RHS-CC.        -   Venation pattern.—Pinnate.        -   Venation color.—Upper surface: RHS 144A (Yellow-green).            Lower surface: RHS 147C (Yellow-green).        -   Color.—Immature: Upper surface: RHS 143A to RHS 144A (Green            to Yellow-green). Lower surface: RHS 146B (Yellow-green).            Mature: Upper surface: RHS 137A (Green). Lower surface: RHS            146B (Yellow-green).        -   Petiole.—Length: Average 0.9 cm. Diameter: Average is            2.5 mm. Color: Upper surface: RHS 146B to RHS 146C            (Yellow-green), with RHS 174A margins (Greyed-orange). Lower            surface: RHS 146C to RHS 146D (Yellow-green), with RHS 174A            margins (Greyed-orange). Texture: Upper surface: Slightly            glossy, margins sparsely covered with very short strigose            hairs, average length: 0.3 mm, colored white; too small and            too sparsely present to be measured with RHS-CC. Lower            surface: Slightly glossy, sparsely covered with very short            strigose hairs, average length: 0.3 mm, colored white; too            small and too sparsely present to be measured with RHS-CC.-   Flowers:    -   -   Natural flowering season.—Mid-summer to late summer.        -   Time to flower.—One season.        -   Fragrance.—Very faint, sweet and pleasant, typical H.            paniculata-scent.        -   Inflorescence type.—Paniculate.        -   Conspicuousness of the fertile flowers of the            inflorescence.—Medium.        -   Panicle.—Shape: Irregular, broad conical. Height: 19.3 cm.            Diameter: 18.9 cm.        -   Peduncle.—Length: 18.7 cm. Diameter: 0.4 cm. Angle: Main            peduncle straight on top of lateral branch (=0°), lateral            peduncles in an average angle of 52.5° to main peduncle.            Strength Moderately strong. Texture: Matte, densely covered            with thin adpressed hairs; average length of hairs 0.4 mm,            RHS 157D (Green-white). Color: RHS 148D (Yellow-green);            sparsely to moderately covered with lenticels, average            length: 1.0 mm, average diameter: 0.5 mm, colored RHS 157A            (Green-white).        -   Sterile florets bud.—Average length: 0.9 cm. Average            diameter: 1.0 cm. Shape: Cup-shaped. Color: RHS 150C            (Yellow-green).        -   Fertile florets bud.—Average length: 0.40 cm. Average            diameter: 0.40 cm. Shape: Broad ovate. Color: RHS 157B            (Green-white) top tinged RHS 62C (Red-purple) base (immature            calyx) RHS 145C (Yellow-green).        -   Sterile florets.—Persistent with an average of 475 of            sterile florets per inflorescence. Aspect: Upright and            outward to slightly drooping. Shape: Rotate. Average            diameter: 4.4 cm. Average depth: 0.6 cm. Longevity of            florets on plant is 6 weeks. Petals: Number per floret: 4,            occasionally 3 or 5. Arrangement: Rotate. Shape: Ovate. Tip:            Acute. Base: Cuneate. Margin: Entire. Length: 0.3 cm. Width:            0.15 cm. Texture: Upper surface: Smooth, glabrous and very            slightly glossy. Lower surface: Smooth, glabrous and matte.            Color when opening: Upper surface: RHS 157A (Green-white)            fading lighter to the margins of RHS 157D. Lower surface:            RHS 145D (Yellow-green), tipped RHS 62B (Red-purple). Color            full open: Upper surface: RHS 157B (Green-white) fading            lighter to the margins of RHS 157D. Lower surface: RHS 157A            (Green-white).        -   Sepals.—Average number: 4 or 5 per floret. Arrangement:            Rotate. Shape: Obovate to broad elliptic. Apex: Shallowly            retuse to obtuse. Base: Narrowly cuneate. Margin: Entire,            occasionally shallowly toothed on upper half. Length:            2.4 cm. Width: 1.8 cm. Texture (both surfaces): Glabrous and            matte. Color: When opening: Upper surface: A blend of RHS            145D (Yellow-green) and RHS 150D (Yellow-green). Lower            surface: Slightly lighter then RHS 145D (Yellow-green),            fading to slightly lighter than RHS 150D toward the top.            Fully opened: Upper surface: RHS 145B (Yellow-green) and RHS            145C (Yellow-green). Lower surface: RHS 145C (Yellow-green).            Fading to: Upper surface: RHS 68C (Red-purple). Lower            surface: RHS 63B (Red-purple) to RHS 63C (Red-purple).        -   Pedicel.—Length: 2.5 cm. Diameter: 0.1 cm. Angle: 40 degrees            to main peduncle. Strength: Moderately strong. Texture:            Matte, very sparsely covered with thin adpressed hairs,            average length of hairs is shorter than 0.04 cm. Color: RHS            157C (Green-white), fading to RHS 145D (Yellow-green) at            proximal end.-   Fertile flowers:    -   -   Number of fertile flowers per inflorescence.—500.        -   Aspect.—Upright.        -   Shape.—Rotate, petals drop when maturing.        -   Diameter.—0.75 cm.        -   Depth.—0.5 cm.        -   Flower longevity.—Five days.        -   Persistent or self-cleaning.—Self-cleaning.        -   Petals.—Petals per flower: 5. Arrangement: Rotate. Shape:            Ovate, moderately concave. Tip: Acute. Base: Cuneate.            Margin: Entire. Length: 0.3 cm. Width: 0.15 cm. Texture:            Upper surface: Smooth, glabrous, very slightly glossy. Lower            surface: Smooth, glabrous matte. Color when opening: Upper            surface: RHS 157A (Green-white), fading lighter toward RHS            157D margins. Lower surface: RHS 145D (Yellow-green), tipped            RHS 62B (Red-purple). Color fully open: Upper surface: RHS            157B (Green-white), fading lighter RHS 157D toward the            margins. Lower surface: RHS 157A (Green-white).        -   Sepals.—Number: 5. Arrangement: Rotate. Shape: Deltoid. Tip:            Broad acuminate. Base: Broad cuneate. Margin: Entire.            Length: 0.15 cm. Width: 0.12 cm. Texture: Both surfaces:            Glabrous matte. Color when opening: Upper surface: RHS 145D            (Yellow-green). Lower surface: RHS 145C (Yellow-green).            Color fully open: Upper surface: RHS 145D (Yellow-green).            Lower surface: RHS 145C to RHS 145D (Yellow-green).        -   Pedicel.—Length: 0.2 cm. Diameter: 0.05 cm. Angle: 20            degrees to main peduncle. Strength: Moderate. Texture:            Matte, moderately to densely covered with a thin pubescence;            average length of hairs: 0.3 mm, colored white to            green-white; too small and too sparsely present to be            measured with RHS-CC. Color: RHS 145C to RHS 145D            (Yellow-green).-   Reproductive organs:    -   -   Sterile flowers.—Androecium: Present. Stamens: 8. Filament            length: 0.2 cm. Filament color: RHS NN155A (White). Anther            shape: Broad oblong. Anther length: 0.075 cm. Anther color:            RHS 157A (Green-white). Pollen amount: Low to moderate.            Pollen color: RHS 156D (Greyed-white). Gynoecium: Present.            Pistils per floret: 2. Pistil length: 0.2 cm. Stigma shape:            Club-shaped. Stigma color: RHS 145C (Yellow-green). Style            length: 0.125 cm. Style color: RHS 145D (Yellow-green).            Ovary: Not present.        -   Fertile flowers.—Stamens: 10. Filament length: 0.25 cm.            Filament color: RHS NN155B (White). Anther shape: Broad            oblong. Anther length: 0.075 cm. Anther color: is RHS 157A            (Green-white) and slightly darker. Pollen amount: Low to            moderate. Pollen color: RHS 156D (Greyed-white). Pistils: 3.            Pistil length: 0.2 cm. Stigma shape: Club-shaped. Stigma            color: RHS 145C to RHS 145D (Yellow-green). Style length:            0.1 cm. Style color: RHS 145D (Yellow-green). Ovary color:            RHS 145D (Yellow-green).-   Seed: Not observed.-   Disease and pest resistance: The disease which are occur in H.    paniculata and also in COUSTAR02 are: white fly, black spots,    powdering mildew, lice.

COMPARISON WITH PARENTAL LINES

The parental lines for ‘COUSTAR02’ are unknown so no comparisoninformation is available.

COMPARISON TO KNOWN VARIETY

‘COUSTAR02’ is most similar to the commercial Hydrangea plant named‘ILVOBO’ (U.S. Plant Pat. No. 22,782). Differences between the twovarieties are described in Table 1:

TABLE 1 Comparison with Similar Variety Variety Commercial lineCharacteristic ‘COUSTAR02’ ‘ILVOBO’ Fertile petals Upper surface: RHS157B Fully opened, upper (fully open) (Green-white), fading lighter andlower surfaces: RHS 157D toward the margins Close to 155C. Lowersurface: RHS 157A (Green-white) Fertile floret bud Color: RHS 157B(Green- Close to 155C white) top tinged RHS 62C (Red-purple) base(immature calyx) RHS 145C (Yellow- green) Pedicel color RHS 145C to RHS145D Close to RHS 155A

I claim:
 1. A new and distinct cultivar of Hydrangea Plant Named‘COUSTAR02’ as described and illustrated herein.